Study links repeated poor litters to lower recovery odds in sows
Bottom line
Version 1
A new Frontiers in Veterinary Science study suggests that one poor litter in a commercial sow often isn’t the whole story. Researchers analyzed 15,699 farrowing records from 4,498 sows in one commercial breeding herd from 2020 to 2026 and found that 62.4% of low-performing parities, defined as 10 or fewer piglets weaned, recovered at the next consecutive parity. But recovery fell as poor performance repeated: from 63.8% after a first low-performing parity to 58.0% after two in a row and 46.9% after three or more. The authors conclude that reproductive history across parities may be more informative for retention decisions than the most recent litter alone. (frontiersin.org)
Why it matters: For veterinarians and production teams, the findings support a more longitudinal approach to sow retention and culling decisions. A single underperforming parity may be transient, while repeated underperformance appears more predictive of future risk. That matters in a sector where early-parity losses already weigh on productivity, welfare, and herd economics, and where reproduction is a leading reason for removals between parity 1 and parity 2. (frontiersin.org)
What to watch: Whether these findings are validated across additional commercial herds, as the authors note, and whether producers begin adjusting retention protocols to incorporate parity-by-parity reproductive history more explicitly. (frontiersin.org)
Key facts
- Study type
- Retrospective study
- Journal
- Frontiers in Veterinary Science
- Sample size
- 15,699 farrowing records from 4,498 commercial sows
- Setting
- One commercial breeding herd
- Study period
- 2020 to 2026
- Low performance definition
- 10 or fewer piglets weaned per litter
- Overall recovery rate
- 62.4% of low-performing parities recovered at the next consecutive parity
- Recovery after repeated low performance
- 63.8% after one low-performing parity, 58.0% after two in a row, and 46.9% after three or more
- Publication status
- Accepted September 17, 2026
Version 2
A newly published Frontiers in Veterinary Science study adds nuance to a familiar production question: when should a low-performing sow be retained, and when should she be culled? Using 15,699 farrowing records from 4,498 commercial sows, the authors found that most sows recovered after a single low-performing parity, but the odds of recovery dropped meaningfully when underperformance repeated across successive parities. (frontiersin.org)
The study addresses a practical gap in sow management. Reproductive underperformance is commonly used to guide retention and replacement, but a poor litter in isolation may not reflect persistent reproductive failure. In this dataset, low performance was defined as 10 or fewer piglets weaned per litter, the 25th percentile of the herd’s observed distribution, and recovery meant exceeding that threshold at the immediately following consecutive parity. (frontiersin.org)
Among 2,948 low-performance episodes with an observed next consecutive parity, 62.4% recovered. Recovery was 63.8% after a first observed low-performing parity, 58.0% after two consecutive low-performing parities, and 46.9% after three or more. After adjustment for reproductive and temporal factors, two consecutive low-performing parities were associated with 27% lower odds of recovery, and three or more with 45% lower odds, compared with a first low-performing parity. Adjusted recovery probabilities after repeated underperformance were 61.0% in early parities, 55.1% in prime parities, and 41.3% in later parities, though the stage-by-history interaction was not statistically significant and the authors treated those patterns as exploratory. (frontiersin.org)
That pattern fits broader industry concerns around sow longevity and early-parity loss. PigCHAMP benchmark reporting notes that annual culling rates commonly run 40% to 50%, that many sows are replaced before their third parity, and that reproduction failure is a leading reason for losses between parity 1 and parity 2. In a separate industry technical article, PIC’s Sergio Canavate said most removals through culling or death occur between parity 1 and parity 2 because of reproductive, locomotion, or other health issues, underscoring how much pressure there is to make better keep-or-cull decisions earlier in a sow’s productive life. (pigchamp.com)
There doesn’t appear to be much outside commentary yet on this specific paper, which was accepted on September 17, 2026, and is still awaiting its final formatted version on the journal site. But the study’s message aligns with earlier work suggesting that early-parity reproductive records can help predict later performance, and with longstanding herd-management thinking that repeated fertility problems carry more decision-making weight than a single bad cycle. (frontiersin.org)
Why it matters: For veterinary professionals advising sow farms, the practical takeaway is that context matters. If a sow underperforms once, immediate removal may sacrifice animals that would recover at the next parity. But if underperformance repeats, the probability of rebound appears to fall enough that reproductive history becomes a stronger risk signal. That can support more defensible retention protocols, tighter herd monitoring, and better conversations with production teams about welfare, replacement flow, and the economics of involuntary culling. Better record quality will be essential if farms want to apply this kind of parity-history approach consistently. (frontiersin.org)
What to watch: The key next step is external validation. This was a single-herd retrospective study, and the authors explicitly say the findings should be tested across other commercial systems before being generalized broadly. If follow-up studies confirm the signal, veterinarians may see more farms move from litter-by-litter decisions toward structured retention models that weigh repeated underperformance, parity stage, and whole-sow history together. (frontiersin.org)